Kidneys are essentially blood cleansing organs. A person's kidneys serve several vital functions, including the removal of waste from the body in the form of urine; filtration of toxins from the blood; and providing an appropriate concentration of some important nutrients, including potassium and calcium, in the blood. To achieve these functions, an artery from the heart brings blood into the kidneys, where the blood is passed through, and is cleaned by, a network of millions of tiny units called nephrons. The nephrons filter out toxins, excess nutrients and body fluid and excrete them in the form of urine into the bladder. After being cleaned and filtered, the blood passes from the kidneys, through veins, and back into circulation.
For those instances when a person's kidneys don't function properly, a process called dialysis has been developed and is in widespread use. Essentially, dialysis artificially replaces the functions of the kidney. There are two distinct types of dialysis: hemodialysis and peritoneal dialysis. Hemodialysis involves removing blood from the body and filtering it in a machine. The patient is connected by a tube to the dialysis machine, which continuously draws blood out of the patient, and then contacts that blood with a membrane in a dialyzer. The other side of the membrane contains a continuously circulating aqueous solution called dialysate. Excess fluid and toxins flow from the blood, through the membrane, and into the dialysate, thereby cleansing the blood. Salts and other nutrients may pass from the dialysate, through the membrane and into the blood. After passing through the dialyzer, the cleansed blood is returned to the patient. For many patients, hemodialysis is performed for 3 to 4 hours at least three times a week. It is usually performed at a dialysis center, although home dialysis is also possible.
Peritoneal dialysis is also known as internal or in-body dialysis. Like hemodialysis, peritoneal dialysis entails the use of a blood-cleansing solution called dialysate; the composition of a dialysate for peritoneal dialysis is typically different from the composition of dialysate for hemodialysis. In peritoneal dialysis, dialysate is infused into the peritoneal cavity (the region of the abdomen that is lined by the peritoneum). While in the peritoneal cavity, the dialysate functions to extract toxins and excess fluid from the blood. After a period of time, the solution is drained from the body cavity, taking with it the undesired toxins and excess fluid.
Further information regarding dialysis and kidney function may be obtained through, for example, the American Society of Nephrology (www.asn-online.com, Washington, D.C.).
The present invention identifies and solves problems with existing dialysis, identifies new opportunities for dialysis, and provides further related advantages as disclosed more fully herein.